1. Field of the Invention
The present invention relates generally to a method and apparatus for wirelessly charging multiple wireless power receivers, and more particularly, to a method and apparatus for wirelessly charging multiple wireless power receivers using a single wireless power transmitter.
2. Description of the Related Art
Wireless charging technology uses wireless power transmission and reception to, for example, charge a battery of a cell phone by placing the cell phone on a charging pad without using a separate physical charging connector, e.g., a charging cable.
The wireless charging technologies include an electromagnetic induction method using coils, a resonance method using resonance, and a Radio Frequency (RF)/micro wave radiation method that converts electrical energy into microwaves for transmission.
However, systems using these conventional wireless charging technologies have a problem that if a total sum of capacities of wireless power receivers to be charged exceeds an output capacity of a wireless power transmitter, the wireless power receivers cannot receive the wireless power. Thus, if there are multiple wireless power receivers to be wirelessly charged at the same time, transmission/reception of the wireless power often cannot be performed in the conventional wireless power transmission systems.